6640471 has 4 divisors (see below), whose sum is σ = 6645744. Its totient is φ = 6635200.

The previous prime is 6640463. The next prime is 6640477. The reversal of 6640471 is 1740466.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 6640471 - 2³ = 6640463 is a prime.

It is a super-3 number, since 3×6640471³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (6640477) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 486 + ... + 3676.

It is an arithmetic number, because the mean of its divisors is an integer number (1661436).

Almost surely, 2^6640471 is an apocalyptic number.

6640471 is a deficient number, since it is larger than the sum of its proper divisors (5273).

6640471 is a wasteful number, since it uses less digits than its factorization.

6640471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5272.

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 6640471 is about 2576.9111354488. The cubic root of 6640471 is about 187.9603715326.

The spelling of 6640471 in words is "six million, six hundred forty thousand, four hundred seventy-one".